Shareholders are widening their ranks against Syms as the retailer looks to deregister its shares under federal securities laws, a week after delisting from the New York Stock Exchange.

A lawsuit by a New Jersey-based investor seeking class-action status, accuses the Secaucus, N.J.-based clothing chain of “self-dealing” as it moves to deregister its shares and as a result avoid financial disclosures to the Securities and Exchange Commission.

Syms management has said the disclosures – which are required under Sarbanes-Oxley accounting rules – are costly and time-consuming. But the suit, which has been reviewed by The Post, alleges that Syms’ estimate that it will save $750,000 a year by going dark is “inflated.” And the figure “pales in comparison” to the $100 million in market capitalization lost since Syms announced on Dec. 21 its intention to delist and deregister its shares, according to the suit.

“The going-dark plan was conceived and approved . . . without any safeguards to protect the interest of Syms minority shareholders,” the suit alleges.

Two other big shareholders that together own nearly 10 percent of Syms – Barington Capital and Esopus Creek Advisors – have sued separately to block Syms’ recent moves. Some shareholders fear the company is looking for a cheap way to take Syms private and seize its valuable real estate – including its lease on Park Avenue and its store on Trinity Place near Wall Street.

Some shareholders say Syms’ real-estate holdings – which include owned properties among the chain’s 33 nationwide stores – could be worth more than $15 a share. Syms shares – which had traded around $17 last month before the company announced its delisting and deregistration plans – closed yesterday at $10.20 on the Pink Sheets, an electronic-based over-the-counter market.

CEO Marcy Syms declined to comment on the lawsuit seeking class-action status, saying she hadn’t yet seen it. But in an interview earlier this week, she said Syms has no plans to go private. Rather, it plans to save money by posting financial results on the Web in order to avoid the costly fees associated with making SEC filings, she said.

“We’re cutting out the middleman,” Syms said, likening the moves to the retailer’s off-price apparel strategy.

Syms aims to deregister April 1. But to do so, it must have fewer than 300 shareholders of record under securities laws. Syms admitted this week that the roster has surged lately – to roughly 200 when it delisted its shares last week, from around 100 when it first announced its plans late December.

Indeed, some Syms investors have encouraged their peers to register shares in their own names instead of their brokers’ in an effort to bring the shareholder count above 300.

“People should give shares to their children, grandchildren, aunt, uncle, mother and father,” said Thomas Graham Kahn, president of Kahn Brothers & Co., a New York investment firm that owns “a few hundred thousand” Syms shares.